1. Field of the Invention
This invention relates generally to electrical jackfields and is concerned more particularly with an electrical jackfield having a linear array of juxtaposed jack modules and respective aligned printed circuit boards which are frontally removable from the jackfield.
2. Discussion of the Prior Art
A jackfield assembly may comprise a housing having therein a linear array of electrical jack modules which are disposed in side-by-side relationship along a front portion of the housing to have respective plug-receiving end portions extend through a front panel of the housing. In a U.S. patent application, Ser. No. 20,938, filed on Mar. 2, 1987, there is disclosed a channelized jackfield having a housing wherein a plurality of substantially planar channels extend in juxtaposed relationship from a front portion to an opposing rear portion of the housing. Each of the channels has inserted therein, through a front opening of the housing, a respective tri-jack module with a slab-like body having a narrow side uppermost in the housing. Also, each of the channels has inserted therein, through a rear opening of the housing, a respective printed circuit board which is disposed on edge within the housing.
Each of the tri-jack modules has a plug-receiving end portion comprising a vertically extending front plate having protruding therefrom a vertical series of three mutually spaced sleeves which extend through a front panel covering the front opening of the housing. In each of the modules there is a stacked array of three electrical jacks, each of which is aligned with a respective sleeve extending through the front plate of the module. Each of the electrical jacks comprises a plurality of electrical switches having respective moveable leaf spring members electrically engageable with respective stationary members. Also, the moveable members of an electrical jack are disposed for actuation by a patch cord end plug inserted through the aligned sleeve. The end plug has mutually insulated portions shaped for electrically contacting respective moveable members of the electrical jack.
The moveable members and the stationary members of the electrical switches comprising the three electrical jacks stacked in each module are attached to respective terminals which extend in a linear array from a rear portion of the module adjacent the aligned printed circuit board. The terminals in the linear array extend into electrical engagement with respective contacts of a connector secured to the adjacent end portion of the printed circuit board. Contacts of the connector are electrically connected through respective conductors of the printed circuit board to respective terminal lugs which extend from an opposing end portion of the printed circuit board. The terminal lugs project out of the rear opening of the housing for electrical connection, as by wirewrapping, for example, to respective conductors of an umbilical wire harness.
In U.S. Pat. No. 4,772,562 there is disclosed a channelized jackfield similar to the described jackfield but having a split front panel. The split front panel provides means for inserting or removing an individual jack module and the aligned printed circuit board as a unitary subassembly from the front of the housing without disturbing the patch cord connections between the other modules of the linear array. However, this embodiment has the drawback that all of the terminal lugs extending from the printed circuit boards project out of the rear of the housing. The housing may be mounted in a tier of racks which extends linearly over a considerable distance, such as thirty feet, for example. As a result, if a testing technician wishes to connect a wire to or disconnect a wire from a terminal lug when inserting a patch cord end plug into a sleeve of a jack module, the terminal lugs are not readily accessible from the front of the jackfield assembly. Consequently, the testing operation usually requires two technicians, one technician at the rear of the rack for connecting or disconnecting the wires and the other technician at the front of the rack for inserting the patch cord end plug or with drawing it from the sleeve of a jack module.